Surface characteristics and wetting behavior of carbon nanotubes

2004 ◽  
Vol 858 ◽  
Author(s):  
Asa H. Barber ◽  
Luqi Liu ◽  
Sidney R. Cohen ◽  
H. Daniel
Keyword(s):  
Carbon Nanotubes ◽  
Contact Angle ◽  
Organic Liquid ◽  
Surface Characteristics ◽  
Resultant Force ◽  
Chemical Changes ◽  
Wetting Behavior ◽  
Wetting Properties

ABSTRACTThe wetting properties and surface characteristics of individual carbon nanotubes are elucidated by immersing the nanotube into various organic liquid. The resultant force acting on the nanotube can be used to evaluate a liquid contact angle at the nanotube surface from classical methods. This technique was shown to be accurate enough to discern differences in wetting behavior due to both structural and chemical changes in the nanotube structure.

scholarly journals Wetting Behavior of the Ag-5CuO Brazing Alloy on ZTA Composite Ceramic with/without CuO Coating in Air

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 609
Author(s):  
Guangjie Feng ◽  
Manqin Liu ◽  
Yalei Liu ◽  
Zhouxin Jin ◽  
Yifeng Wang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Triple Line ◽  
Composite Ceramic ◽  
Heating Process ◽  
Wetting Behavior ◽  
Subsequent Heating ◽  
Rich Liquid ◽  
Zirconia Toughened Alumina ◽  
Pure Al2o3

The wetting of Ag-5 wt.% CuO (Ag-5CuO) alloy on initial/CuO-coated zirconia toughened alumina (ZTA) composite ceramic in air was studied in detail. The results showed that the contact angle of the Ag-5CuO/ZTA system rapidly decreased from 81° at 970 °C to 45° at 990 °C during the heating process, however, moderate reductions in contact angle were observed in the subsequent heating and temperature holding stages. In comparison with the contact angle of pure Al2O3, an increment of about 4° of the stable contact angle of Ag-5CuO alloy on the heterogeneous ZTA was observed. The reaction between Al2O3 and CuO can reduce the damage of the CuO-rich liquid to ZrO2 in the ZTA substrate. Both oxygen and CuO were helpful in reducing the contact angle of Ag on ZTA and enhancing the bonding of the Ag/ZTA interface. The continuous CuO coating on ZTA and the monotectic liquid containing more CuO in the region near the triple line induced reductions of more than 40° and about 10° in the contact angle, respectively, between the initial and the CuO coating-improved wetting systems.

scholarly journals Biomimetic Approach for the Elaboration of Highly Hydrophobic Surfaces: Study of the Links between Morphology and Wettability

Biomimetics ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Quentin Legrand ◽  
Stephane Benayoun ◽  
Stephane Valette
Keyword(s):  
Contact Angle ◽  
Ginkgo Biloba ◽  
Contact Angle Hysteresis ◽  
Contact Angles ◽  
Textured Surfaces ◽  
Replication Process ◽  
Wetting Behavior ◽  
Static Contact ◽  
Biomimetic Approach ◽  
Highly Hydrophobic

This investigation of morphology-wetting links was performed using a biomimetic approach. Three natural leaves’ surfaces were studied: two bamboo varieties and Ginkgo Biloba. Multiscale surface topographies were analyzed by SEM observations, FFT, and Gaussian filtering. A PDMS replicating protocol of natural surfaces was proposed in order to study the purely morphological contribution to wetting. High static contact angles, close to 135∘, were measured on PDMS replicated surfaces. Compared to flat PDMS, the increase in static contact angle due to purely morphological contribution was around 20∘. Such an increase in contact angle was obtained despite loss of the nanometric scale during the replication process. Moreover, a significant decrease of the hysteresis contact angle was measured on PDMS replicas. The value of the contact angle hysteresis moved from 40∘ for flat PDMS to less than 10∘ for textured replicated surfaces. The wetting behavior of multiscale textured surfaces was then studied in the frame of the Wenzel and Cassie–Baxter models. Whereas the classical laws made it possible to describe the wetting behavior of the ginkgo biloba replications, a hierarchical model was developed to depict the wetting behavior of both bamboo species.

Preparation and the Blood Compatibility of Titanium Oxide Nanorod Arrays

2011 ◽  
Vol 306-307 ◽  
pp. 25-30 ◽  
Author(s):  
Ping Luo ◽  
Zhan Yun Huang ◽  
Di Hu Chen
Keyword(s):  
Contact Angle ◽  
Surface Morphology ◽  
Titanium Oxide ◽  
Tin Oxide ◽  
Growth Parameters ◽  
Blood Compatibility ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Nanorod Arrays ◽  
Wetting Properties

In this work, titanium oxide nanorod arrays were fabricated by using the hydrothermal method on fluorine-doped tin oxide (FTO) coated glass. The diameter of the nanorods could be controlled from 150 nm to 30 nm by changing the growth parameters. The surface morphology and the structure of the samples were characterized by SEM and XRD. The wetting properties were identified by contact angle measurement. Platelet attachment was investigated to evaluate the blood compatibility of the samples with different nanoscale topographies. Results show that the nanotopographical surfaces perform outstanding blood compatibility, and the adhering platelet decreased with the increasing diameter of the nanorods.

Synthesis of aligned carbon nanotubes in organic liquids

2002 ◽  
Vol 17 (9) ◽  
pp. 2457-2464 ◽  
Author(s):  
Yafei Zhang ◽  
Mikka N.-Gamo ◽  
Kiyoharu Nakagawa ◽  
Toshihiro Ando
Keyword(s):  
Carbon Nanotubes ◽  
Organic Liquid ◽  
Film Surface ◽  
Normal Pressure ◽  
Organic Liquids ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Aligned Carbon Nanotubes ◽  
Novel Method ◽  
The Right

A simple and novel method was developed for efficient synthesis of aligned multiwalled carbon nanotubes (CNTs) in methanol and ethanol under normal pressure. The CNTs' alignment and structures were investigated using Raman scattering and x-ray diffraction spectroscopy. A unique kind of coupled CNT was synthesized in which one rotated to the left and one rotated to the right. Chains periodically bridged the coupled CNTs. The growth mechanism of the CNTs within organic liquid is proposed to be a catalytic process at the Fe film surface in a dynamic and thermal nonequilibrium condition in organic liquids.

Wettability of CNT-Doped Solder under Isothermal Aging

2016 ◽  
Vol 857 ◽  
pp. 76-78
Author(s):  
Norliza Ismail ◽  
Roslina Ismail ◽  
Nur Izni Abd Aziz ◽  
Azman Jalar
Keyword(s):  
Carbon Nanotubes ◽  
Contact Angle ◽  
Isothermal Aging ◽  
Optical Microscope ◽  
Image Analyzer ◽  
Solder Paste ◽  
Reflow Process ◽  
Weight Percentage ◽  
Test Board ◽  
Free Solder

Wettability for lead free solder 99.0Sn-0.3Ag-0.7Cu (SAC237) with addition of different weight percentage carbon nanotube after thermal treatment was investigated. SAC 237 solder powder with flux was mixed with 0.01%, 0.02%, 0.03% and 0.04% carbon nanotubes (CNTs) to form SAC-CNTs solder paste. Printed solder paste on test board with Cu surface finish was then reflow under 270°C temperature and isothermal aging at 150°C for 0,200 and 400 hours. Wettability of SAC-CNT solder was determined by measuring contact angle using optical microscope and image analyzer. As a result, from reflow process right through 400 hours of thermal aging, SAC237 with 0.04% CNT has the lowest contact angle as compared to other SAC-CNTs and SAC237 solder. As a conclusion, addition of carbon nanotubes into solder SAC237 improved their wettability on Cu substrate, especially at 0.04% of CNTs.

Surface Topography Induced Ultrahydrophobic Behavior: Effect of Three-Phase Contact Line Topology

2006 ◽  
Author(s):  
Neeharika Anantharaju ◽  
Mahesh Panchagnula ◽  
Wayne Kimsey ◽  
Sudhakar Neti ◽  
Svetlana Tatic-Lucic
Keyword(s):  
Contact Angle ◽  
Contact Line ◽  
Anomalous Behavior ◽  
Contact Angles ◽  
Wet Etching ◽  
Surface Geometry ◽  
Wetting Behavior ◽  
Void Fractions ◽  
Three Phase ◽  
Receding Contact

The wettability of silicon surface hydrophobized using silanization reagents was studied. The advancing and receding contact angles were measured with the captive needle approach. In this approach, a drop under study was held on the hydrophobized surface with a fine needle immersed in it. The asymptotic advancing and receding angles were obtained by incrementally increasing the volume added and removed, respectively, until no change in angles was observed. The values were compared with the previously published results. Further, the wetting behavior of water droplets on periodically structured hydrophobic surfaces was investigated. The surfaces were prepared with the wet etching process and contain posts and holes of different sizes and void fractions. The surface geometry brought up a scope to study the Wenzel (filling of surface grooves) and Cassie (non filling of the surface grooves) theories and effects of surface geometry and roughness on the contact angle. Experimental data point to an anomalous behavior where the data does not obey either Wenzel or Cassie type phenomenology. This behavior is explained by an understanding of the contact line topography. The effect of contact line topography on the contact angle was thus parametrically studied. It was also inferred that, the contact angle increased with the increase in void fraction. The observations may serve as guidelines in designing surfaces with the desired wetting behavior.

scholarly journals Relationship among the firing temperature, wetting properties and colonization of fungi on clay roofing tile surfaces

2011 ◽  
pp. 197-207
Author(s):  
Jonjaua Ranogajec ◽  
Sinisa Markov ◽  
Ognjen Rudic ◽  
Snezana Vucetic ◽  
Vilma Ducman
Keyword(s):  
Water Absorption ◽  
Firing Temperature ◽  
Surface Characteristics ◽  
Surface Phenomenon ◽  
Experimental Investigations ◽  
Surface Wetting ◽  
Wetting Properties ◽  
Deterioration Process ◽  
Two Temperatures ◽  
Two Stages

The wettability of clay roofing tiles as a surface phenomenon plays a key role considering their deterioration process during exploitation. The experimental investigations in this paper were performed combining the data of the material-relevant parameters and the surface wetting properties in order to assess clay roofing tiles biodurability. The fungus Aspergillusniger was used as a model microorganism whose colonization and growth, during a period of 28 days on the tiles fired at two temperatures (900 and 1020?C), was analyzed. The paper confirms that the colonization of the tiles with the fungus goes through two stages: up to the 18th day, based on the surface characteristics, and after the 18th day when the textural characteristics (values of water absorption) are the dominant parameters.

Macroscopic Wetting Behavior and a Method for Measuring Contact Angles

1990 ◽  
Vol 112 (3) ◽  
pp. 289-295 ◽  
Author(s):  
K. Katoh ◽  
H. Fujita ◽  
H. Sasaki
Keyword(s):  
Contact Angle ◽  
Solid Surface ◽  
Liquid Surface ◽  
Contact Angles ◽  
Critical Height ◽  
Solid Cone ◽  
Wetting Behavior ◽  
Conventional View ◽  
The Subject ◽  
Thermodynamic Instability

Macroscopic wetting behavior is investigated theoretically from a thermodynamic viewpoint. The axisymmetric liquid meniscus formed under a conical solid surface is chosen as the subject of the theoretical analysis. Using the meniscus configuration obtained by the Laplace equation, the total free energy of the system is calculated. In the case of the half vertical angle of the cone φ = 90 deg (horizontal plate), the system shows thermodynamic instability when the meniscus attaches to the solid surface at the contact angle. This result, unlike the conventional view, agrees well with the practical wetting behavior observed in this study. On the other hand, when 0 deg < φ < 90 deg, the system shows thermodynamic stability at the contact angle. However, when the solid cone is held at a position higher than the critical height from a stationary liquid surface, the system becomes unstable. It is possible to measure the contact angle easily using this unstable phenomenon.

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